…r performance.
Caches the output of get_item_schema() to avoid redundant recomputation of translatable strings and other computed values. This method is called many times per item in each REST request, and the results of the method should not vary between calls.
Additional schema fields are not cached.
Props kadamwhite, joehoyle, TimothyBlynJacobs.
Fixes #47871.
git-svn-id: https://develop.svn.wordpress.org/trunk@45811 602fd350-edb4-49c9-b593-d223f7449a82